Ok I can't find any info on this and have only treated canine diabetes which is the same as in humans.
My son was told that as his blood sugar level lowers, he is to increase insulin. That doesn't make sense to me. His "normal" has been over 400 and with insulin is 200-ish at present. He insists the lower it goes the more insulin he needs to take. If this is true, I am worried that he won't get more.
If the first amount of insulin is only currently bringing him down to the 200s, then yes, he does need more. Once it is normalized, then additional insulin will not be required, just the amount to keep him stable. That may be what he means.